Experts say current cuffless methods for measuring blood pressure, like the tech found in Samsung Galaxy Watch, can only reliably track relative changes
Nicole Wetsman / The Verge : Tweets: @berci and @spjuraschek Tweets: @berci : #Smartwatch-measured blood pressure #tech is not ready just yet. “Measuring blood pressure is much harder than tracking heart rate and rhythm, and getting it right is arguably even more important.” - writes The @verge. #themedicalfuturist #digitalheal 👉https://www.theverge.com/ ... https://twitter.com/... Stephen Juraschek MD, PhD / @spjuraschek : Great quotes in @verge by experts @jordy_bc and @AnnMarieNavar. I'm not convinced cuffless devices even get relative changes right independent of heart rate. But if that's the claim I hope validation protocols require they demonstrate it! https://www.theverge.com/...
Context & Ripple Effects
When The Verge's Nicole Wetsman reported this expert skepticism in 2021, cardiologists including Stephen Juraschek and Jordy (@jordy_bc) were warning that cuffless wrist tech — Samsung Galaxy Watch included — could not yet be trusted for absolute blood pressure numbers, only relative trends. That caution proved predictive rather than passing: Apple subsequently struggled enough with accuracy that it delayed its own blood pressure monitor, and Samsung's eventual US rollout leaned on a traditional upper-arm cuff for calibration.
The arc since then has split into two camps: devices that admit they track direction, not levels, and challengers claiming cuff-grade readings — most recently Vital Signals' $399 Signal Ring. The expert consensus in this article is the yardstick every subsequent claim gets measured against.
First-order effects
- Galaxy Watch owners and clinicians reading its output must treat the numbers as relative indicators of change, not diagnostic blood pressure values — a limitation Samsung itself implicitly acknowledged by requiring an arm-cuff calibration in its later US blood pressure rollout.
Second-order effects
- Apple's accuracy difficulties during testing turned into a multi-year delay, ceding the wearable blood pressure feature race to Samsung while it works toward a reading it can defend clinically.
Third-order effects
- The wearables market is bifurcating into trend-tracking devices and those claiming cuff-equivalent accuracy — and if regulators or doctors hold the line these experts drew, only validated absolute readings will earn the clinical trust the Apple Watch has so far lacked with physicians.
The trend: Consumer wearables are converging on clinically defensible blood pressure measurement, with each vendor's claim tested against the expert threshold that relative tracking alone does not count.